The invention generally relates to data transmission networks and, more particularly, the invention relates to tracking the history of channel based network devices.
Emulated local area networks (xe2x80x9cELANSxe2x80x9d) emulate a local area network that utilizes a non-channel based data transmission protocol (e.g., a broadcast data transmission protocol, such as Ethernet, that is commonly used by local area networks). Accordingly, from the perspective of other network devices in a given ELAN, all network devices coupled to an Ethernet switch implementing the given ELAN appear to be Ethernet devices. This includes network devices utilizing a channel-based data transmission protocol (e.g., asynchronous transfer mode).
Asynchronous Transfer Mode (xe2x80x9cATMxe2x80x9d) is a well known channel-based data transmission protocol that utilizes virtual channels to transmit data from a transmitting site to a receiving site. More specifically, a virtual channel typically is established (i.e., initialized) prior to message transmission, and subsequently utilized to transmit all message data during a single data transmission (xe2x80x9csessionxe2x80x9d). Accordingly, for a given session, all data cells (i.e., 53 byte data packets) of a message utilize the same virtual channel as they are transmitted from the transmitting site to the receiving site.
When joining an ELAN, each ATM device registers with one or more Ethernet switches implementing the ELAN. Once registered with such switches, the status of each such ATM device is entered into a database. In particular, data indicating that each registered ATM switch is a member of the ELAN is entered into a registration database that is administered by a controller (e.g., a LAN emulation server) executing on the Ethernet switch. Conversely, when the given ATM switch is removed from the ELAN, the registration database is updated to delete data relating to the given ATM switch. Accordingly, among other things, the registration database maintains a listing of all active ATM network devices (and other channel-based network devices) that are members of the ELAN.
Problems arise on an ELAN when one or more channel-based network devices repeatedly are joined to and released from an ELAN. For example, such activity can indicate a resource problem in the ELAN. Accessing the registration database does not identify such network devices, however, since the registration database merely shows a listing of channel based network devices currently in the ELAN.
In accordance with one aspect of the invention, a method and apparatus for determining the history of at least one network device (the xe2x80x9cgiven devicexe2x80x9d) in a set of channel-based network devices coupled to a network maintains a history memory to generate a history of the given device. To that end, the current status of the given device is recorded in the history memory at one or more selected times. In preferred embodiments, the current status is retrieved at the selected times from a registration memory that includes the current status of the given network device. A reply message with device data relating to the given device responsively is generated in response to receipt of an inquiry message requesting information about the given device. The device data represents at least one of the current status and the history of the given device.
Once generated, the reply message may be forwarded to an administrator network device. In preferred embodiments, the set of network devices are members of an emulated local area network. The current status may be recorded in the history memory by polling the registration memory every polling interval, and updating the history memory based upon the data retrieved from the registration memory during each polling interval. During each polling interval, the history memory may be updated by recording data indicating the current status of the at least one of the set of network devices.
In preferred embodiments, the given device communicates via the asynchronous transfer mode protocol. The network also may include a LAN network device that communicates with other network devices in the network at least in part via a non-channel based protocol. For example, the LAN network device may communicate via the Ethernet protocol. In addition, the history for the given device preferably is stored in a management information base.
In accordance with another aspect of the invention, an apparatus and method of tracking the history of a given network device (that is a member of a set of network devices utilizing a channel based protocol) accesses a registration memory to determine the current status of the given network device, and records the determined current status in a history memory. The act of recording the current status produces history data for the given network device. Similar to the previously noted aspect of the invention, the current status of each member of the set of network devices is stored in the registration memory.
In preferred embodiments, the history data for the given network device is retrieved from the history memory in response to a request for such data. Such request may be receipt of a request message requesting the data. The history data then is included in a history message that may be forwarded to another network device coupled to the network. Among other things, the channel-based protocol may be the asynchronous transfer mode protocol. The current status may be recorded in the history memory once during every preselected interval. Such interval may be a polling interval. Moreover, the history of the network device may be stored in a management information base within the history memory. The history data for the given network device preferably indicates if the given network device is a member of the network at various times.
In accordance with other aspects of the invention, an apparatus and method of determining the history of a given network device utilizing a channel based protocol forwards an inquiry message from a first network device to a second network device. The inquiry message may request information about the given network device. The current status of the given network device preferably is recorded in a history memory associated with the second network device. The current status may be recorded at one or more selected times and be retrieved from a registration memory having the current status. The act of recording the current status preferably produces a history of the given network device. In response to receipt of the inquiry message, a reply message is generated having device data representing at least one of the current status and the history of the given network device. Once generated, the reply message is forwarded to the first network device.
In preferred embodiments, the device data is extracted from the reply message and displayed on a graphical user interface on the first network device. A configuration graphical user interface also may be displayed on the first network device. Such interface may include fields for entering polling data for polling the registration memory.
Preferred embodiments of the invention are implemented as a computer program product having a computer usable medium with computer readable program code thereon. The computer readable code may be read and utilized by the computer system in accordance with conventional processes.